FIELD OF THE INVENTION
The invention relates to a contact with a silver contact base, which is soldered to a contact carrier by means of a silver intermediate layer and a solder. The invention also relates to a method for making the contact. Among other uses, such contacts are used in relays and switches of the most varied kinds.
The solders required for soldering are commercially available as flat material. They already contain metered additives as soldering aids. It is known for strips of contact solder and pure silver to be joined together by hot rolling and for flat solder material then to be rolled as a third layer onto the two-layer strip. The contacts are then cut from the resultant three-layer strip and soldered onto the contact bearers or carriers. It is a peculiarity of that production process that the rolled edges have to be trimmed, so that waste is involved. Cutting apart the contacts is also becoming increasingly problematic, if the contact thicknesses are great.
It is also known to make two-layer contacts from a silver intermediate layer which is cut to contact dimensions and from a press-on silver contact base, and then to solder those contacts onto the respective contact carrier by using a solder and soldering aids. With that mode of operation no waste is produced, as long as strip material is used that matches the width or length of the later contact at least in its width. In larger quantities, however, that mode of operation is relatively complicated, because exact positioning and metering of the solder and soldering aid is required.